The present invention relates to novel prostacyclin derivatives, a process for their preparation, and to their use as medicinal agents.
(5E)- and (5Z)-6a-carbaprostaglandin I.sub.2 analogs are disclosed in German Unexamined Laid-Open Applications DOS's 2,845,770; 2,900,352 (U.S. Pat. No. 4,322,435); 2,902,442 (U.S. Pat. No. 4,307,112); 2,904,655 (U.S. Pat. No. 4,238,414); 2,909,088; 3,048,906; and 2,912,409. The nomenclature of the compounds of this invention is based on a proposal by Morton and Brokaw (J. Org. Chem. 44 : 2880 [1979]). The synthesis of these compounds yields in all cases two double-bond isomers characterized by the symbols (5E) or (5Z). The two isomers of this prototype are clarified by the following structural formulae: ##STR5##
It is known from the very voluminous state of the art of prostacyclins and their analogs that this class of compounds is suited, due to its biological and pharmacological properties, for the treatment of mammals, including man. The use of these compounds as medicinal agents, however, frequently meets with difficulties since their period of effectiveness is too short for therapeutic purposes. All structural modifications attempt to increase the duration of effectiveness as well as the selectivity of efficacy